Arc-extinguishing device



R ,T. PIERCE.

ARC EXTINGUISHING DEVICE.

APPLICATION FILED FEB. 4. 1918.

1,308,256. Patented July 1, 1919.

wmuzsszs INVENTOR I Ra a/14mm? W H BY ATTORNEY UNITED, STATES PATENT OFFICE.

RAYMOND T. PIERCE, 01 WILKINSBURG, I'ENNSYLVANIA, ASSIGNOR TO WEST- INGHOUSE ELECTRIC 8c 'MANUFACTUBING COMPANY, A CORPORATION OF PENNSYLVANIA.

Specification of Letters Patent.

Patented July 1, 1919.

Application filed February 4,.1918. Serial No. 215,386.

To all whom it may concern:

Be it known that I, RAYMOND T. PIERCE, a citizenof the United States, and a resident of Vilkinsburg, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Arc-Extinguishing Devices, of which the following is a specification.

-My invention relates to electrical systems of distribution and particularly to apparatus for extinguishing arcs that occur in such systems without disturbing the operation of the apparatus connected thereto.

One object of my invention is to provide a device of the above-indicated character that shall alternately open and close a circuit interrupter to so reduce the voltage of the circuit that the arc will be extinguished without causing the, apparatus connected to the circuit to fall out of synchronism.

Another object of my invention is to provide a device of the above-indicated character that shall comprise. means responsive to the drop in voltage across the circuit interrupter for restoring the same and means for opening the voltage connection across the interrupter when the arc has persisted' for a predetermined period of time.

Copending application. Serial No. 83,786, filed March 13, 1,916. by F. E. Ricketts discloses a device for alternately opening and closing a circuit interrupter in accordance with the difference in potential on the respective sides of the interrupter and means for preventing the closing of the interrupter after the are has persisted for a predetermined period of time.

In my invention, I provide an overload relay for tripping the interrupter, a transformer connected across the corresponding terminals of the interrupter. means, responsive to the voltage of the transformer. for reclosing the interrupter and a time-limit relay that is also responsive to the drop in voltage across the interrupter for open-'circuiting the transformer after the arc has ex-. isted for a predetermined period of time to thereby prevent the reclosingof the inter rupter. By this arrangement. a minimum number of relays may be employed and an effective and reliable arc-suppressing device be provided.

The single figure of the accompanying drawing is a diagrammatic view of a distributing circuit that is provided with are extinguishing means embodying my invention.

A generator 1 supplies energy to conductors 2, 3 and 4 of a distributing circuit 5 that is provided with an interrupter 6 which is adapted to be tripped when an overload or an arcing ground occurs upon the circuit 5 and to be immediately recloscd in order that the load which is connected to the circuit may not fall out of synchronism. That is, if the circuit interrupter 6 is tripped, the voltage upon the load end of the circuit 5 is reduced substantially to zero and, if the overload is caused by an arcing ground, the arc will be extinguished because of the lack of voltage to maintain it.

The circuit interrupter 6 is provided with a tripping electromagnet. 7 and a closing electromagnet 8. A series transformer 9 is operatively connected to the circuit 5 and is adapted to energize the winding 10 of an overload relay 11. The relay 11 is adapted to operate substantially instantaneously upon the occurrence of an overload for the purpose of completing a circuit, from conductor 12 of a circuit 13, comprising a source 14 of elcctromotive force, through the. tripping electromagnet'? to the other conductor 15 of the circuit 13. T hus, when an overload or ground occurs upon the circuit 5, the interrupter 6 will be tripped.

The primary winding 16 of a transformer 17 is connected to the corresponding terminals 4 of the interrupter (i. and the primary winding 18 oi a similar transformer 19 is connected to the corresponding terminals 3 of the interrupter (i. A two-pole circuit interrupter 20. the respective poles of which are connected inseries with the windings 16 and 18 of the transformers 17 and 19. respectively, is biased toward its open position by a spring 21 and is held in its closed position by a latch 22.

connected in parallel relation with respect to each other. and the circuit. thus constituted, is connected in series relation with the winding 25 of a time-limit relay device 26 of the motor-meter type having no control springs and the winding 27 of a relay 28. The contact members 29 of the time-limit relay 26 are adapted. when engaged, to complete a circuit from the conductor 15 of the circuit 13 through the winding 30 of an electromagnet 31 to the conductor 12 of the circuit 13. The contact members 32 of the relay 23 are. adapted to complete a circuit from the conductor 12 of the circuit 13 through the closing electromagnct 8 of the interrupter (3 to the conductor 15 of the circuit 13.

'hen an overload occurs upon the circuit 5. the relay 11 will be actuated to energize the tripping electromagnet 7 and thereby open the interrupter 6. However. when the circuit interrupter 6 is opened. sutiicient drop in potential across the windings 16 and 18 of the transformers 17 and 19 will obtain to effect operation of the relays 25 and 28. When the relay operates, the closing electromagnet h is energized to close the inter" rupter 6.

In case the are still exists on the circuit 5 after the interrupter (S is closed. the relay 11 will again be operated to eifccttripping of the interrupter 6. This operation of the tripping and closing the interrupter will continue for a period of time controlled by the time setting of the relay 96. That is, the time setting of the relay 26 is such that. after the interrupter (3 is opened and closed a predetermined number of times. which should be sutlicient to extinguish a temporary arcing ground. the contact members 29 will be closed to thereby cause the electro magnet 31 to release the latch 32 and permit the spring 21 to open the circuit interrupter 20. \Vhen the circuit interrupter 20 is opened. the transformers 17 and 19 are dei nergized to permit the relay 2 to return to its initial position. In order 'to reclose the interrupter (5 after the operation of the relay 26. the interrupter 20 must be manually closed.

I do not limit my invention to the par ticular structure illustrated as it may he variously modified within the scope of the invention set forth in the appended claims.

I claim as my invention: y

1. In a system of distribution. the combination with a circuit interruptt and means for opening it when an arc obtains on the systen'i. of a transformer connected across the interrupter. a relay dependent upon the .voltage of the transformer for reclosing the interrul'itcr. and'a time-limit relay for open circuiting the transformer after the interrupter has been opened and closed a predetermined number of times.

2. In a system of distribution. the combination with a circuit interrupter and means for opening it when an arc obtains on the System. of a transformer connected across the two terminals of the interrupter. means responsive to the voltage of the transformer for reclosing the interrupter. and means for open-circuiting the transformer when the arc persists for a predetermined interval of time.

3. In a system of distribution, the combination with a circuit interrupter and means for opening it. when an arc obtains on the system, of a transformer connected across the two terminals of the interrupter. means responsive to the voltage of the transformer for reclosing the interrupter. and means for open-circuiting the transformer when the arc persists for a predetermined interval of time to render the reclosing means inoperative.

l. In a system of distribution, the combination with a circuit interrupter and means for opening it when an arc obtains 011 the system. of a transformer connected across the two terminals of the interrupter. electrical means for reclosing the interrupter when voltage is impressed on the transformer, and means for disconnecting the transformer to preclude the reclosing of the interrupter if the arc persists for a predetermined interval of time.

In a system of distribution. the combi nation with a circuit interrupter and means for opening it when an arc obtains on the system. of means responsive to the voltage across the terminals of the interrupter for reclosing the same. and means for rendering' said voltage-responsive means inoperative after the arc has persisted for a predetermined interval of'time.

6. In a system of distribution. the combination with a circuit interrupter and means for opening it when an arc obtains on the system. of a transformer the primary winding of which is connected across the terminals of the interrupter. means connected to the secondary winding of the transformer for reclosing the interrupter. and means for open-circuiting the primary winding of the transformer under predetermined conditions.

7. In a system of distribution. the combination with a circuit interrupter and means for opening it when an arc obtains on the system. of a transformer the primary winding of which is connected across the termi- 8. In a system of distribution, the comhiopen-circuitin'g the primary winding of the nation with a circuit interrupter and means transformer if the arc persists for a pre- 10 for opening it when an arc obtains on the determined interval of time. system, of a transformer the primary wind- In testimony whereof, I have hereunto ing of which is connected across the termisubscribed my name this 30th day of J an., nals of the interrupter, means connected 1918. to the secondary winding of the transformer for reelosing the interrupter, and means for RAYMOND T. PIERCE. 

